1 files changed, 110 insertions, 8 deletions

diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c
index a4b451c6addf..940b142cc11f 100644
--- a/arch/x86/kernel/xsave.c
+++ b/arch/x86/kernel/xsave.c
@@ -8,6 +8,7 @@
 
 #include <linux/bootmem.h>
 #include <linux/compat.h>
+#include <linux/cpu.h>
 #include <asm/i387.h>
 #include <asm/fpu-internal.h>
 #include <asm/sigframe.h>
@@ -24,7 +25,9 @@ u64 pcntxt_mask;
 struct xsave_struct *init_xstate_buf;
 
 static struct _fpx_sw_bytes fx_sw_reserved, fx_sw_reserved_ia32;
-static unsigned int *xstate_offsets, *xstate_sizes, xstate_features;
+static unsigned int *xstate_offsets, *xstate_sizes;
+static unsigned int xstate_comp_offsets[sizeof(pcntxt_mask)*8];
+static unsigned int xstate_features;
 
 /*
  * If a processor implementation discern that a processor state component is
@@ -283,7 +286,7 @@ sanitize_restored_xstate(struct task_struct *tsk,
 
         if (use_xsave()) {
                 /* These bits must be zero. */
-                xsave_hdr->reserved1[0] = xsave_hdr->reserved1[1] = 0;
+                memset(xsave_hdr->reserved, 0, 48);
 
                 /*
                  * Init the state that is not present in the memory
@@ -479,6 +482,52 @@ static void __init setup_xstate_features(void)
 }
 
 /*
+ * This function sets up offsets and sizes of all extended states in
+ * xsave area. This supports both standard format and compacted format
+ * of the xsave aread.
+ *
+ * Input: void
+ * Output: void
+ */
+void setup_xstate_comp(void)
+{
+        unsigned int xstate_comp_sizes[sizeof(pcntxt_mask)*8];
+        int i;
+
+        /*
+         * The FP xstates and SSE xstates are legacy states. They are always
+         * in the fixed offsets in the xsave area in either compacted form
+         * or standard form.
+         */
+        xstate_comp_offsets[0] = 0;
+        xstate_comp_offsets[1] = offsetof(struct i387_fxsave_struct, xmm_space);
+
+        if (!cpu_has_xsaves) {
+                for (i = 2; i < xstate_features; i++) {
+                        if (test_bit(i, (unsigned long *)&pcntxt_mask)) {
+                                xstate_comp_offsets[i] = xstate_offsets[i];
+                                xstate_comp_sizes[i] = xstate_sizes[i];
+                        }
+                }
+                return;
+        }
+
+        xstate_comp_offsets[2] = FXSAVE_SIZE + XSAVE_HDR_SIZE;
+
+        for (i = 2; i < xstate_features; i++) {
+                if (test_bit(i, (unsigned long *)&pcntxt_mask))
+                        xstate_comp_sizes[i] = xstate_sizes[i];
+                else
+                        xstate_comp_sizes[i] = 0;
+
+                if (i > 2)
+                        xstate_comp_offsets[i] = xstate_comp_offsets[i-1]
+                                        + xstate_comp_sizes[i-1];
+
+        }
+}
+
+/*
  * setup the xstate image representing the init state
  */
 static void __init setup_init_fpu_buf(void)
@@ -496,15 +545,21 @@ static void __init setup_init_fpu_buf(void)
 
         setup_xstate_features();
 
+        if (cpu_has_xsaves) {
+                init_xstate_buf->xsave_hdr.xcomp_bv =
+                                                (u64)1 << 63 | pcntxt_mask;
+                init_xstate_buf->xsave_hdr.xstate_bv = pcntxt_mask;
+        }
+
         /*
          * Init all the features state with header_bv being 0x0
          */
-        xrstor_state(init_xstate_buf, -1);
+        xrstor_state_booting(init_xstate_buf, -1);
         /*
          * Dump the init state again. This is to identify the init state
          * of any feature which is not represented by all zero's.
          */
-        xsave_state(init_xstate_buf, -1);
+        xsave_state_booting(init_xstate_buf, -1);
 }
 
 static enum { AUTO, ENABLE, DISABLE } eagerfpu = AUTO;
@@ -520,6 +575,30 @@ static int __init eager_fpu_setup(char *s)
 }
 __setup("eagerfpu=", eager_fpu_setup);
 
+
+/*
+ * Calculate total size of enabled xstates in XCR0/pcntxt_mask.
+ */
+static void __init init_xstate_size(void)
+{
+        unsigned int eax, ebx, ecx, edx;
+        int i;
+
+        if (!cpu_has_xsaves) {
+                cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx);
+                xstate_size = ebx;
+                return;
+        }
+
+        xstate_size = FXSAVE_SIZE + XSAVE_HDR_SIZE;
+        for (i = 2; i < 64; i++) {
+                if (test_bit(i, (unsigned long *)&pcntxt_mask)) {
+                        cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
+                        xstate_size += eax;
+                }
+        }
+}
+
 /*
  * Enable and initialize the xsave feature.
  */
@@ -551,8 +630,7 @@ static void __init xstate_enable_boot_cpu(void)
         /*
          * Recompute the context size for enabled features
          */
-        cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx);
-        xstate_size = ebx;
+        init_xstate_size();
 
         update_regset_xstate_info(xstate_size, pcntxt_mask);
         prepare_fx_sw_frame();
@@ -572,8 +650,9 @@ static void __init xstate_enable_boot_cpu(void)
                 }
         }
 
-        pr_info("enabled xstate_bv 0x%llx, cntxt size 0x%x\n",
-                pcntxt_mask, xstate_size);
+        pr_info("enabled xstate_bv 0x%llx, cntxt size 0x%x using %s\n",
+                pcntxt_mask, xstate_size,
+                cpu_has_xsaves ? "compacted form" : "standard form");
 }
 
 /*
@@ -635,3 +714,26 @@ void eager_fpu_init(void)
         else
                 fxrstor_checking(&init_xstate_buf->i387);
 }
+
+/*
+ * Given the xsave area and a state inside, this function returns the
+ * address of the state.
+ *
+ * This is the API that is called to get xstate address in either
+ * standard format or compacted format of xsave area.
+ *
+ * Inputs:
+ *      xsave: base address of the xsave area;
+ *      xstate: state which is defined in xsave.h (e.g. XSTATE_FP, XSTATE_SSE,
+ *      etc.)
+ * Output:
+ *      address of the state in the xsave area.
+ */
+void *get_xsave_addr(struct xsave_struct *xsave, int xstate)
+{
+        int feature = fls64(xstate) - 1;
+        if (!test_bit(feature, (unsigned long *)&pcntxt_mask))
+                return NULL;
+
+        return (void *)xsave + xstate_comp_offsets[feature];
+}